Halsey Gulick became Head of School at a time of economic desperation at Proctor leading him to find "win-win" situations that benefited students and the school. A "General Course" was offered for boys seeking practical skills in machine work, woodworking, carpentry, boat building, and auto mechanics. “Improvement Squads" built tennis courts, mowed lawns, fought fires, delivered coal, constructed The Cabin, cut ski trails and installed a rope tow lift. It was on this foundation that Proctor’s “Skills” classes in the arts evolved and a culture of service became rooted in the community.

Lyle Farrell's tenure as Head of School focused on strengthened academics, growing student enrollment and the construction of new facilities. Nicknamed "the great builder," Farrell turned to Trustees for financial support of capital projects including an addition to Maxwell Savage Hall, Shirley Hall, athletic fields, the Proctor Ski Area and Farrell Field House. However, Farrell's greatest impact was establishing an academic support program inspired by the research of Samuel T. Orton providing opportunities for bright, hard-working students with learning differences.

An iconoclastic visionary, David Fowler empowered Proctor's faculty to define the policies and programs of their school. The result was revolutionary. Proctor became co-educational immediately. Relationships between students and faculty became informal and non-adversarial; seniority systems were abolished, and the value of hands-on, real-world educational experience was reflected in Wilderness Orientation, Project Period, Mountain Classroom, and language immersion programs in Spain and France. To nurture Proctor's "soul," David introduced regular all-school assemblies at which anyone was welcome to speak. The school found and embraced distinctly human values.

A lifelong student of teaching methodologies and learning styles, Steve Wilkins led Proctor on a decade of self-analysis studying everything from sleep needs and the academic schedule to gender issues in classrooms. Figuratively, he held a mirror to the community and asked, "How can we be the best at what we do?" He posited that increased support enabled increased academic challenge. Those simple, bold assertions fueled a Capital Campaign that saw the construction of Carriage House, the Teddy Maloney ‘88 Rink, the Wise Center, and a state-of-the-art music/recording studio. Steve’s greatest legacy is the adoption of teaching methodologies that established a standard for college preparation.

Throughout his 17 year tenure, Mike Henriques championed the mission, values, and essential character of Proctor while guiding the community with a clear and exciting new vision for enhanced residential life and student wellness programs. The school's market position became recognized with greater clarity resulting in increased demand for admission, low student attrition, and record-breaking annual giving as well as more than $60M in capital projects: Brown Dining Commons, Farrell Field House, Outdoor Center, turf fields, major upgrades to the Proctor Ski Area, and three new dormitories. Mike worked tirelessly to ensure Proctor lived out its mission in all areas of school life.

On July 1, 2021, Brian Thomas began his tenure as Proctor's Head of School. A native of Robbins and Harvey, Illinois (on Chicago’s far south side), Brian graduated from Yale University (BA in History) and Portland State University (MS in Education), and has spent thirty years in independent school education preparing for this opportunity to lead Proctor. He was attracted to Proctor because of its deep commitment to experiential learning, the off-campus experience of its students, and its educational model rooted in supporting, embracing, and challenging all learning styles. During his first two years at Proctor, Brian has evolved the school’s leadership structure and challenged the school to extend access to students farthest from opportunity, while immersing himself in all Proctor has to offer.

Steve Wilkins rejoined the Proctor community as Interim Head of School for the 2024-2025 school year, bringing with him more than 40 years of independent school experience and expertise in neuroscience, the adolescent brain, and how Proctor can lead in the world of supporting and challenging diverse learners.